I wonder, but do not know, the motivation or the mental state of Eddie Ray Routh, the 25-year old former Marine now being held for the Saturday murders in Texas of former Navy SEAL sniper Chris Kyle and fellow military veteran Chad Littlefield.

But I want to advance some possible theories. In time, we may discover more.

The obvious one to the public, and the one getting all of the attention so far, is post-traumatic stress disorder.

PTSD is technically an anxiety disorder. The definition is changing at this time, but as it stands it is defined like this:

— There is a traumatic experience, accompanied by feelings of fear and helplessness.

— There is a cluster of symptoms, including re-experiencing intrusive memories, numbness, and exaggerated reactions.

— There is an impairment in functioning.

Another possibility is psychosis.

— Psychosis, by definition, is a lack of contact with reality, usually accompanied by delusions or hallucinations. The most common mental disorder with psychosis is schizophrenia, which often presents in the early 20s.

Substance abuse is a third possible cause.

Alcohol is, of course, commonly abused. However, other substances, such as PCP, methamphetamines, and the newer synthetic marijuana (K2, spice, etc.) often cause psychosis.

How to sort these out?

Normally there will be an evaluation by a psychiatrist or psychologist, especially trained in this area (a “forensically trained psychiatrist or psychologist”). He or she will do an evaluation to find out whether PTSD, psychosis, substance abuse, or a combination, may have played a role in the accused mindset at the time of the crime.

The evaluation will consist of a clinical interview, gaining information from other sources such as family and friends, and may include psychological testing. The latter may include the ink-blot Rorschach test, the MMPI (the Minnesota Multiphasic Personality Inventory) test, and other tools.

I am a forensic psychiatrist. I try to figure out whether someone is mentally ill, and – if so — whether they should be judged not criminally responsible or not guilty by reason of insanity due to such impairments.

Another theory is he converted to islam while stationed in Iraq. Sympathized with the insurgents and went after Chris Kyle for their revenge. This is bolstered by the fact he was not a "combat" veteran and was never diagnosed with PTSD. it should all come out eventually but certainly not thru the media.

There are some seriously maladjusted individuals in todays society. This man has sacrificed so much in his life to ensure these morons have a safe place to sleep, enjoy the guarantee of freedom and liberty yet the handful of ignorant comments below simply blows my mind. No one person here is at fault. All these men served and all likely had some form of PTSD. This is the plight of todays warrior, on the front lines, pushing himself, selflessly, through the harshest climates, terrains and the most barbaric of cultures in order to seek out and destroy the enemies of nations which put the people, independance and equality first. Anyone that has never been there, from the training to the frontlines will never understand. I would prefer for those to try and not understand or comprehend these things. The missions and battles these men have fought are for only these men. Common ordinary souls not wired in such a way are better put to use in other ways. So turn on your central air/heat, grab an ice cold beer/tea, light a cig or pack a dip, pick up your PS3 controller throw in Call of Duty or, whatever high speed covert ops games there are these days, take a seat on your comfy "never get rid of it" couch or lazy boy and play away. Its that simple-right?

@jalangaya He was fighting for our country. I guess next time our soldiers get in a fight with the terrorists we will just "talk it out" with them while they are killing our soldiers. Will that make you feel better? Oh, and while he was out "bragging" about killing them as you would say he was donating all of his proceeds to the families whose family member/members who have died protecting our country including ignorant people like you who like to cowardly post things such as you did. God Bless The Kyle Family and Littlefield family as well! You died trying to help someone and as heroes and will live on as legends!

@MarkDeegan So that gives you the right to come on here and be disrespectful and preach your nonsense when someone just died? Man, you must have been raised poorly because you're lacking in manners and common courtesy. Once again, you are an unpatriotic clown.

I like the 'fighting for our Country' argument. How exactly does sending
troops over to the Middle East help our country? What benefit has the
average American enjoyed from our decade long occupation of Afghanistan?
Our military does not fight for our Country the way most people
define it. They fight for a handful of people in Washington DC, who
mostly make poor decisions for political reasons. Killing and death are
always destructive and regrettable, whether here or in some country
where we don't know the victims.